JP2005045611A - Image forming apparatus - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a technique for adding identification information that does not present in an original image in a very inconspicuous way and printing the identification information concerning the image forming technology. <P>SOLUTION: An inputting part 122 receives image data. A color space converting part 124 converts the color space of the image data into color space, for example, of CMYK, etc., that is used at the time of printing and outputs the color space to a thresholding part 126. The thresholding part 126 performs dither conversion in each of cyan, magenta, yellow, and black, and outputs the results to an identification information adding part 130. The identification information adding part 130 replaces a part of image dots forming an image with information dots forming identification information to generate print data and outputs the print data to a printing part 140. Through the processes, identification information formed by a combination of dots can be added to a printed matter. <P>COPYRIGHT: (C)2005,JPO&NCIPI

Description

  The present invention relates to an image forming technique, and more particularly to a technique for adding information to an original image.

Copiers, scanners, and printers have been developed for the purpose of faithfully reproducing original images. In recent years, technological progress has been remarkable, and the copying function, scanning function and printing function have been highly developed, and can be reproduced with such high accuracy that they cannot be distinguished from the original image. For this reason, for example, banknotes and securities may be copied and used illegally. There is a technique for clarifying a copy image by adding information that is not included in the original image to such an image that should not be copied (see, for example, Patent Document 1).
JP-A-6-62217

  In the technique disclosed in Patent Document 1, the symbol pattern is made inconspicuous by modulating the density of the symbol pattern for identifying the copy image according to the density of the original image. However, since the symbol pattern is added to the original image before binarization, if the symbol pattern is small or the density difference is small, the symbol pattern may be corrupted and buried during binarization. Therefore, a certain amount of size and density difference are necessary so that the symbol pattern is not buried in the original image.

  The present invention has been made in view of these points, and an object of the present invention is to provide a technique for printing by adding identification information not included in an original image so as to be inconspicuous.

  One embodiment of the present invention is an apparatus for forming an image. The apparatus includes: means for receiving input of image data; means for converting image data into print data; means for providing identification information for specifying a printed material formed based on the print data; Means for replacing part of the data with identification information. Thereby, for example, the identification information is not buried by the process of converting image data such as dither conversion into print data. Further, since a part of the printing data is replaced with the identification information, the identification information can be formed for each dot forming the printed matter. That is, since the identification information can be expressed by a combination of dots, the identification information can be added so as not to be very noticeable.

  The apparatus may further include means for determining a position where the printing data in the printing data is replaced with the identification information in accordance with the density, brightness, or luminance of the printed material formed based on the image data. Thereby, according to the color of the dot which forms identification information, identification information can be added to the position where the dot is not conspicuous.

  Another embodiment of the present invention is an apparatus for forming an image. The apparatus includes a unit that receives input of image data, and a generation unit that includes predetermined identification information and generates printing data for forming a printed material based on the image data. The generation unit includes the identification information. The printing data is generated so that the identification information is formed by combining dots having substantially the same size as the dot size forming the printed material around the print position.

  It should be noted that any combination of the above-described constituent elements and a conversion of the expression of the present invention between a method, an apparatus, a system, a recording medium, a computer program, etc. are also effective as an aspect of the present invention.

  According to the present invention, it is possible to add a dot for forming identification information with substantially the same size as a dot forming a printed matter. Accordingly, it is possible to add identification information to the original image so as to be inconspicuous, appropriately protect the original image, and provide a highly practical image forming apparatus.

  FIG. 1A is a diagram illustrating an example of a printed material 10 in which identification information 30 is attached to an original image by the method according to the embodiment. In this figure, the identification information 30 is added to the area 14 as a combination of print units (hereinafter simply referred to as “dots”) in the dither pattern. The area 14 is a portion in the original image where the dot size and color at the time of printing are substantially the same as the dot size and color added as the identification information 30.

  Generally, when printing image data, the image data is dither converted based on a dither pattern. By this conversion, the shading in each part is expressed by the dot size and the density. The dots for forming the original image are hereinafter referred to as “image dots”. In the present embodiment, the identification information 30 is expressed as a combination of dot arrangements such as Braille. Then, dots for forming the identification information 30 (hereinafter simply referred to as “information dots”) are formed at positions of image dots that are substantially the same as the size of the information dots. In other words, image dots having substantially the same size are replaced with information dots. When the original image is color, for example, information dots are formed using a color that is difficult for humans to visually recognize, such as a portion with a low density or a portion with high brightness or luminance. Thereby, the identification information 30 can be added so as not to be very conspicuous in the original image.

  FIG. 1B is an enlarged view of the region 14 in FIG. In this figure, the dither matrix 16 is described as an auxiliary line, but this auxiliary line is not actually printed. In this figure, the identification information 30 is formed by a first pattern 12a, a second pattern 12b, and a third pattern 12c (hereinafter simply referred to as “dot pattern 12”). Each dot pattern 12 forming the identification information 30 is formed by arranging information dots 20 in any of 3 rows and 2 columns. For example, numerals and characters are associated with each dot pattern 12. Moreover, the combination of the information dots 20 that form the individual dot patterns 12 is arbitrary and is appropriately defined according to the necessary information amount. Further, the dot size of each information dot 20 forming the identification information 30 is uniform.

  The identification information 30 is arranged at a location where an image dot 22 having a size substantially the same as the size of the information dot 20 exists and the color of the image dot 22 is low in visibility such as yellow. The identification information 30 is formed by regularly arranging a plurality of dot patterns 12 at a predetermined interval. For this reason, the size and color of the image dot 22 are substantially the same as the size and color of the information dot 20, and the image dot 22 exists substantially uniformly in a wider range than the area necessary for forming the identification information 30. The identification information 30 is arranged at the place to be.

  Thus, by adding the identification information 30 with a combination of information dots 20 having a lattice interval of the dither matrix 16 and a dot size of the image dot 22 existing in the vicinity, the dot size can be made extremely inconspicuous. High recognition can be secured. By such a method, individual information such as a serial number or information unique to a printing device can be added as identification information 30 to each printed matter.

  FIG. 2 is an internal configuration diagram of the image forming apparatus 100 according to the embodiment. In terms of hardware components, each component of the image forming apparatus 100 is a CPU, a memory, a program for realizing the components shown in the figure loaded in the memory, a ROM for storing the program, a RAM, and a hard disk. However, it will be understood by those skilled in the art that there are various modifications in the implementation method and apparatus. Each figure to be described below shows functional unit blocks, not hardware unit configurations.

  The image forming apparatus 100 may be an apparatus that performs printing based on image data, such as an MFP (Multi Functional Peripheral), a copying apparatus, and a printing apparatus. For example, the scanner unit 110 reads an original image to be copied and outputs the image data to the print data generation unit 120. The print data generation unit 120 determines a position to which the identification information 30 described with reference to FIG. 1A is added based on the image data, and generates print data designated to add the identification information 30 to the position. To do. Then, the print data generation unit 120 outputs the print data to the printing unit 140. Based on the print data, the printing unit 140 forms the printed matter 10 to which the identification information 30 is added as described with reference to FIGS. 1 (a) and 1 (b).

  The scanner unit 110 includes a reading unit 112, an A / D 114, a shading correction circuit 116, and an image processing unit 118. The reading unit 112 is a line sensor, a CCD (Charge Coupled Diode), or the like, for example, reads an image printed on paper or other print medium, and outputs a voltage value determined by the density of each pixel to the A / D 114. The A / D 114 converts a voltage value that is analog data into digital data, and outputs the digital data to the shading correction circuit 116.

  Since the reading unit 112 optically reads an image, for example, a difference in light amount occurs between both ends and the center of the image according to the positions of the light source and the CCD. The shading correction circuit 116 corrects an error caused by the light amount difference. The image processing unit 118 performs various processes for improving the image quality of the read image such as gamma correction, smoothing, and edge enhancement, and outputs the image data to the print data generation unit 120.

  The print data generation unit 120 includes an input unit 122, a color space conversion unit 124, a binarization unit 126, and an identification information addition unit 130. The input unit 122 inputs image data via the scanner unit 110 or the network 50 and outputs the image data to the color space conversion unit 124. The input unit 122 may input image data via a storage medium such as a flexible disk or a memory card. The color space conversion unit 124 converts the color space of the image data into a color space suitable for printing such as CMYK. Then, the color space conversion unit 124 supplies the image data converted into CMYK to the binarization unit 126. The binarizing unit 126 performs dither conversion for each of cyan (C), magenta (M), yellow (Y), and black (K), and supplies each data to the identification information adding unit 130 as print data.

  The identification information adding unit 130 receives information for specifying a low-density part, a lightness or a bright part from the color space conversion unit 124, and adds the identification information 30 in FIG. 1A based on the information. Determine the position. Then, the identification information adding unit 130 replaces the image dot corresponding to the position with an information dot for forming the identification information 30. In the present embodiment, the identification information 30 is formed with yellow information dots. Therefore, the color space conversion unit 124 supplies the yellow (Y) component of the image data to the identification information adding unit 130. And the identification information addition part 130 determines the position which arrange | positions the identification information 30 based on a yellow (Y) component.

  FIG. 3 is an internal configuration diagram of the identification information adding unit 130 of FIG. The dot size setting unit 138 sets the size of information dots when adding the identification information 30, and outputs the size to the addition position determination unit 132. The additional position determination unit 132 detects a position where the identification information 30 should be added based on the size. The position is determined based on the yellow (Y) component supplied from the color space conversion unit 124 of FIG.

  FIG. 4A shows the relationship between the density of yellow (Y) and the brightness. When the brightness is low, the density of yellow (Y) is high. Further, when the brightness is high, the density of yellow (Y) is low. When dither conversion is performed, the density is expressed by the dot size. Therefore, the addition position determination unit 132 in FIG. 3 selects an area where image dots having substantially the same size as the information dot size are uniformly present as the information dot addition position. Further, the size of the area is equal to or larger than the size at which all the dot patterns 12 added as the identification information 30 can be appropriately arranged, and the additional position determination unit 132 selects such an area as the additional position.

  FIG. 4B is a diagram illustrating the relationship between the size of the image dot and the size of the information dot D at the first lightness A, the second lightness B, and the third lightness C of yellow. The addition position determination unit 132 in FIG. 3 finds an area where image dots that are substantially the same as the size of the information dot D are uniformly present, and selects the area where the identification information 30 is added. The additional position determination unit 132 may select an area where yellow image dots in the range from the second lightness B to the third lightness C are uniformly present as a position to which the identification information 30 is added. By doing so, there is no large difference between the sizes of the image dots and the information dots, so that the identification information 30 is not noticeable and the printed matter 10 does not feel strange.

  Returning to FIG. 3, the additional position determination unit 132 outputs the additional position to the replacement unit 136. Also, the identification information providing unit 134 outputs the dot pattern 12 described with reference to FIG. 1B added as identification information to the replacement unit 136. The identification information providing unit 134 outputs, for example, a dot pattern 12 for forming a serial number, information for specifying the image forming apparatus 100 as identification information, to the replacement unit 136. The replacement unit 136 replaces the image dot 22 in FIG. 1B corresponding to the additional position supplied from the additional position determination unit 132 with the information dot 20 supplied from the identification information providing unit 134, and generates print data. . Then, replacement unit 136 outputs the print data to printing unit 140.

  As described above, after binarization by the binarization unit 126 of FIG. 2, the information dots 20 for forming the identification information in units of dither dots are added, so that arbitrary identification information can be changed to an appropriate position. Can be added to. If the identification information is added before binarization, the dot pattern may be destroyed at the time of binarization, so that arbitrary identification information cannot be added at an appropriate position. Further, the additional position determination unit 132 in FIG. 3 may detect a plurality of additional positions with respect to one original image if possible, or may output the detected plurality of additional positions to the replacement unit 136. Good. Then, the replacement unit 136 may replace the image dots 22 at a plurality of additional positions with information dots 20 as identification information. That is, a plurality of pieces of identification information 30 are added to the printed material 10.

  The print data generation unit 120 in FIG. 2 may be incorporated in, for example, a printer driver that supplies print data to a predetermined printer device. When incorporating as a printer driver, the input unit 122 receives, for example, a path of image data to be printed and image data from a predetermined program. Then, the identification information adding unit 130 outputs the print data to the printer device to be controlled. If the printer device has a dither conversion function, the identification information adding unit 130 outputs print data together with information designating that dither conversion is not performed. Thus, since the dither conversion is not performed on the printer device side, the identification information 30 can be appropriately printed at the position added by the identification information adding unit 130.

  The print data generation unit 120 in FIG. 2 may be incorporated in the printer apparatus. When incorporated in a printer device, the input unit 122 receives image data or simply dither-converted print data from a printer driver running on a personal computer or the like. When the input unit 122 accepts image data, the print data to which the identification information 30 is added is generated through the above-described procedure, and is output to the printing unit 140 included in the printer apparatus. When the input unit 122 receives print data, the print data is input to the identification information adding unit 130 without performing any processing in the color space conversion unit 124 and the binarization unit 126. The identification information adding unit 130 specifies an addition position based on the print data, generates print data to which the identification information 30 is added, and outputs the print data to the printing unit 140.

  The print data generation unit 120 in FIG. 2 may add the identification information 30 when the original image to which the identification information 30 should be added is duplicated. In this case, for example, a unit for determining whether or not an image such as banknotes or securities should be prohibited from being copied or an image to which the identification information 30 should be added is further provided. When it is determined that the image should not be duplicated or the image to which the identification information 30 is to be added, the identification information adding unit 130 may add the identification information 30. The determination unit may determine whether or not the image should be prohibited from being copied or the image to which the identification information 30 should be added by a known technique such as pattern matching.

  By adding the identification information 30 to the original image, it is possible to distinguish between the original and the copy even when the scanner function, the print function, etc. are further developed in the future, and the copy that is as close as possible to the original becomes possible. Further, it is possible to avoid a situation in which an original image that should not be duplicated, such as banknotes or securities, is duplicated and used illegally. In addition, since the above-mentioned unauthorized use can be avoided by the technique of adding the identification information 30, the development side can make a leap forward in the technical development to bring it closer to the original with peace of mind.

  The present invention has been described based on the embodiments. This embodiment is an exemplification, and it will be understood by those skilled in the art that various modifications can be made to combinations of the respective constituent elements and processing processes, and such modifications are also within the scope of the present invention. is there.

It is a figure which shows an example of the printed matter which attached | subjected identification information to the original image by the method which concerns on embodiment. It is the figure which expanded the area | region of Fig.1 (a). 1 is an internal configuration diagram of an image forming apparatus according to an embodiment. It is an internal block diagram of the identification information addition part of FIG. It is a figure which shows the relationship between the density of yellow (Y), and the brightness. FIG. 6 is a diagram showing the relationship between the size of image dots and the size of information dots D at yellow first lightness A, second lightness B, and third lightness C.

Explanation of symbols

  10 printed matter, 12 dot pattern, 12a first pattern, 12b second pattern, 12c third pattern, 14 regions, 16 dither matrix, 20 information dots, 22 image dots, 30 identification information, 50 network, 100 image forming apparatus, 110 Scanner unit, 112 reading unit, 114 A / D, 116 shading correction circuit, 118 image processing unit, 120 print data generation unit, 122 input unit, 124 color space conversion unit, 126 binarization unit, 130 identification information addition unit, 132 additional position determination unit, 134 identification information providing unit, 136 replacement unit, 138 dot size setting unit, 140 printing unit.

Claims (3)

Means for receiving input of image data;
Means for converting the image data into print data;
Means for providing identification information for specifying a printed matter formed based on the printing data;
Means for replacing a part of the printing data with the identification information;
An image forming apparatus comprising:   The apparatus further comprises means for determining a position for replacing the printing data in the printing data with the identification information in accordance with the density, brightness, or luminance of a printed matter formed based on the image data. Item 2. The image forming apparatus according to Item 1. Means for receiving input of image data;
Generation means including predetermined identification information and generating printing data for forming a printed matter based on the image data;
With
The generating means generates the printing data so as to form the identification information by combining dots having substantially the same size as the dot size forming the printed matter around the printing position of the identification information. Forming equipment.

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